How to Divide Perennials

Dividing perennials keeps them healthy and vigorous; it also gives you more plants to put around your garden and to share with friends and family.

Instructions

Difficulty: Moderately Easy

Things You’ll Need:

• shovel
• small ax

1. Flowers With Fibrous Roots Different plants require slightly different approaches. For flowers with fibrous roots, use a shovel to dig up the shallow, sometimes loosely knotted roots. They often break apart as they're dug, or you can easily break them apart with your hands. If not, a little prod with the shovel will usually do the trick.
2. Flowers With a Large Root Ball For flowers with a large root ball, dig up the entire root. If the roots won't break apart with the shovel, use a small hand ax to cut them apart. This works best if you lay the root ball on it's side and cut from the sides inward rather than from the top downward. Sometimes you can divide a plant with a large root ball by slicing off portions of the plant from the outside edges rather than digging up the entire plant.
3. Depending on the size of the plant, you'll get anywhere from two divisions to a dozen. The new divisions can than be planted. Cut back the foliage by two-thirds, or to only a few inches high. Prepare the soil where the divisions will be planted. Water the divisions well and keep them well watered for at least the next four weeks. Apply a 2-inch layer of mulch around the plants to protect them from extremes of heat and cold and to conserve moisture.

Tips & Warnings

• Divide spring blooming plants immediately after flowering.
• Divide summer and fall blooming plants in early spring when they have 2-4 inches of top growth.
• In the South and Southwest, divide all but fall bloomers in the fall. They love the cooler, wetter weather of autumn.
• Give your perennials at least four weeks to adjust before they would be exposed to extreme heat or cold.
• Divide perennials on a cool, overcast day in which rain is forecast. Gentle, moist weather helps prevent heat stress on the tender new divisions.